Mule provides options for handling errors called exceptions. There are two categories of exceptions in Mule: system exceptions which occur during application startup or connection failures, and are handled by system exception strategies; and messaging exceptions which occur within flows and are handled by messaging exception strategies. Mule supports five types of messaging exception strategies to handle errors in transactions: default, catch, choice, reference, and rollback strategies. It is best practice to create a global default exception strategy and add reference strategies in flows to refer to the global strategy.

1. MULE
ERROR HANDLING
C H A N D U 1 4 4 3

2. EXCEPTIONS
• Mule provides numerous options for handling errors. Faults that occur within Mule are
referred to as exceptions
• There are two categories of exceptions in mule:
1) System Exceptions
2) Messaging Exceptions

3. SYSTEM EXCEPTION
• Mule invokes a System Exception Strategy when an exception is thrown at
the system-level
• No message is involved, exceptions are handled by system exception strategies
EX: During application start-up or When a connection to an external system fails
• Mule sends exception to registered listener and logs the exception
• If exception is due to connection failure executes reconnection strategy to connect for
a specific number of times

4. MESSAGE EXCEPTION
• Thrown within a flow whenever a message is involved
• Handled by messaging exception strategies
• Mule flow throws an exception, normal flow execution stops and processes transfers to
the message processor sequence within the exception strategy
• Mule supports five types of messaging exception strategies, each of which is capable
of handling errors that occur in flows which process transactions

5. TYPES OF MESSAGING EXCEPTION
STRATEGIES
• Default Exception Strategy
• Catch Exception Strategy
• Choice Exception Strategy
• Reference Exception Strategy
• Rollback Exception Strategy

6. BEST PRACTICE
• Create a global default exception strategy to customize the way
Mule implicitly handles all exceptions that occur in your application.
• Create global exception strategies by defining them outside a flow globalException.xml
• Add reference exception strategy in your flow and refer to global exception strategy
• Set a default global exception strategy by creating a global configuration element and
setting its default exception strategy to a global exception strategy

7. THANK YOU